The Civil Protection coordinator, Luis Felipe Puente, pointed out that the Ministry of Health is still carrying out a count in the hospitals to establish how many people were wounded.

Many people remained in the streets, fearing aftershocks.

For the past two decades, Mexico's seismic alert system, known by the initials CIRES, has provided the city with an early warning of disaster, using a hundred sensors placed along its Pacific coast, where the risk of an quake is greatest.

Mexico sits atop five tectonic plates, whose movement makes it one of the most seismically active countries in the world.

The US Geological Survey put the magnitude slightly lower, at 8.1. Strong aftershocks continue to rattle the town, including a magnitude 5.2 jolt in the early morning.

Pena Nieto said 50 million of Mexico's 120 million people felt the quake.

Emergency crews in Mexico have recovered the body of a police officer buried in rubble, raising to 65 the death toll from this week's 8.1-magnitude quake.

Rodrigo Soberanes, who lives near San Cristobal de las Casas in Chiapas, the state nearest the epicenter, said his house "moved like chewing gum".

The National Seismological Service said in its most recent report that as of midnight Saturday there had been 846 aftershocks of the magnitude-8.2 natural disaster, which struck just off the coast of the southeastern state of Chiapas late Thursday.

At least 65 people were killed in a historically massive quake that struck the southern coast of Mexico Thursday night, leaving cities and towns in rubble as relief supplies and cleanup crews arrive to assist devastated residents, officials confirmed on Saturday. Another, an infant on a respirator, died after the quake triggered a power outage.

He advised people to check their homes and offices for damage and gas leaks.

Four people were also injured in neighboring Guatemala, where President Jimmy Morales flew over affected areas and ordered urgent humanitarian assistance. As of Saturday, officials reported 36 people dead in that town.